Hey guys...I've been gone for a little while but I'm back and in need of some advice...I have a 2008 yamaha r6...Ive been using amsoil 10w40 since it was new...the bike now has almost 16k miles on it. To be honest I'm.getting kinda sick of paying 13 bucks a quart for amsoil...3 quarts of amsoil and a filter cost more than 8qts of Mobil 1 and a filter for my camaro...a little crazy in my opinion. Now my question is I can get castrol tws 10w60 for free...(the oil that's used in the BMW m cars)...has anyone ran this oil in a streetbike? What do you guys think? Will it be okay for say 2500 mile drain intervals? Any adverse affect on the clutch? The owners manual says that I can use 20w40...so I'm not sure about the 10w60..Thanks for any advice